misc: pci_endpoint_test: Aggregate params checking for xfer

Each transfer test functions have same parameter checking code. This patch
unites those to an introduced function.
Signed-off-by: Shunsuke Mie <mie@igel.co.jp>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20220907020100.122588-1-mie@igel.co.jpSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/pci_endpoint_test.c

@@ -332,6 +332,17 @@ static bool pci_endpoint_test_msi_irq(struct pci_endpoint_test *test,
 	return false;
 }
 
+static int pci_endpoint_test_validate_xfer_params(struct device *dev,
+		struct pci_endpoint_test_xfer_param *param, size_t alignment)
+{
+	if (param->size > SIZE_MAX - alignment) {
+		dev_dbg(dev, "Maximum transfer data size exceeded\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static bool pci_endpoint_test_copy(struct pci_endpoint_test *test,
 				   unsigned long arg)
 {
@@ -363,9 +374,11 @@ static bool pci_endpoint_test_copy(struct pci_endpoint_test *test,
 		return false;
 	}
 
+	err = pci_endpoint_test_validate_xfer_params(dev, &param, alignment);
+	if (err)
+		return false;
+
 	size = param.size;
-	if (size > SIZE_MAX - alignment)
-		goto err;
 
 	use_dma = !!(param.flags & PCITEST_FLAGS_USE_DMA);
 	if (use_dma)
@@ -497,9 +510,11 @@ static bool pci_endpoint_test_write(struct pci_endpoint_test *test,
 		return false;
 	}
 
+	err = pci_endpoint_test_validate_xfer_params(dev, &param, alignment);
+	if (err)
+		return false;
+
 	size = param.size;
-	if (size > SIZE_MAX - alignment)
-		goto err;
 
 	use_dma = !!(param.flags & PCITEST_FLAGS_USE_DMA);
 	if (use_dma)
@@ -595,9 +610,11 @@ static bool pci_endpoint_test_read(struct pci_endpoint_test *test,
 		return false;
 	}
 
+	err = pci_endpoint_test_validate_xfer_params(dev, &param, alignment);
+	if (err)
+		return false;
+
 	size = param.size;
-	if (size > SIZE_MAX - alignment)
-		goto err;
 
 	use_dma = !!(param.flags & PCITEST_FLAGS_USE_DMA);
 	if (use_dma)